This invention relates generally to an apparatus and method for reinforcing a tower monopole to which loads in excess of the design capacity will be added. More particularly, the invention relates to an apparatus and method that includes the use of vertical rods distributed around a monopole and fixed to the monopole at spaced intervals to increase monopole capacity and stability.
As wireless telecommunications traffic has increased, so has the need for transmission equipment mounted on poles. The transmission equipment needs to be mounted not only on new poles in new geographic areas by individual wireless service providers, but also by competing service providers who install equipment covering overlapping geographic areas. One solution includes purchasing additional land or easements, applying for the necessary government permits and zoning approvals, and constructing a new tower for the new transmission equipment.
Purchasing land or easements, however, can be an expensive undertaking, especially in urban areas where wireless telecommunications demand may be greatest. Zoning regulations often limit the construction of new towers to be in the vicinity of existing towers, or may prohibit the construction of new towers in a service provider's preferred location. The expense and delay associated with the zoning process may be so great that construction of a new tower is not feasible. Further, once zoning regulations are satisfied and permits are obtained, the service provider then incurs the expense associated with the construction and maintenance of a new tower.
The tower itself must be designed to support the weight of the telecommunications transmission equipment as well as the forces exerted on the pole by environmental factors such as wind and ice. The equipment and the environmental factors produce bending moment forces that may cause a single-pole tower, also referred to as a tower monopole, to overturn if not designed for adequate stability. Traditionally, tower monopoles have been designed to withstand only the forces expected from the equipment originally installed on the pole. Rarely are tower monopoles designed with sufficient stability to allow for the addition of new equipment.
Conventional reinforcing methods include the use of split sleeves that fully encircle the tower monopole, extending from an anchor in the foundation upward on the monopole. Such a system uses a significant amount of materials and is cumbersome to install. Other methods require welding of materials to the monopole, which is difficult given the heights at which the welding must be performed.
Thus, there is a need for a method and an apparatus for increasing the capacity and stability of a single-pole tower that will support the loads of additional equipment as well as the corresponding additional environmental forces exerted on the pole.